Photographs Courtest of GM, Russ Gee, The John And Marge Sawruk Collection, and Geneva Campbell
Part 1: Design and development—’55 to ’67
Illustration by David Kimble / Courtesy of GM
Every time you get behind the wheel of your favorite classic Pontiac, you have more than general managers Semon E. “Bunkie” Knudsen, Elliott M. “Pete” Estes, and John Z. DeLorean to thank for the success of its overhead-valve V-8. Before any of these icons in Pontiac’s history became household names among auto enthusiasts, a group of dedicated engine engineers and scientists were working on moving Pontiac out of the world of the Straight 6 and Straight 8 and into the future of the Pontiac V-8.
Herb Adams, the Pontiac special project engineer who counts the ’69 Trans Am amongst his many accomplishments, began as a student draftsman at Pontiac Motor Division in 1957. He recalls learning the stories of the origins and development of Pontiac’s famous V-8 from Motor Engineer Mark Frank, who warmed up to Adams and shared stories with him in 1968.
“I want High Performance Pontiac readers to know and share these stories that Mark told to me, and those that I had firsthand knowledge of during my career at Pontiac,” he says. “These pioneers of the Pontiac V-8 deserve to have their names remembered, for their work formed the basis for all of the Pontiac V-8 engines of the musclecar era and beyond, including the 389, 421, 326, 400, 428, and 455.”
What follows are Herb’s recollections.
Pontiac’s showroom brochure introduced the new-for-’55 V-8 and heralded its power and perf
Title: Assistant Engine Engineer
Accomplishment: Inventor of the Stamped-Steel Ball Rocker Arms
Prior to his invention of the stamped-steel ball rocker arms, the rocker system used on most of the existing overhead-valve V-8 engines consisted of a ground shaft with forged and machined arms pivoting on it. Clayton reasoned that stamped parts—costing pennies—would result in a big savings. This led him to design the famous stamped-steel ball rocker arms.
Clayton couldn’t get his bosses at Pontiac Engineering to let him work on the project, so in classic hot-rodder style, he made the first ones in his home basement machine shop. When he was able to prove to Pontiac Engineering how well they worked, he was allowed to pursue the project on company time.
Once Pontiac Engineering was satisfied with the design, Clayton had to show it to the manufacturing experts within the Division. Since it was a new idea, they told him it was impossible to produce. To prove them wrong, Clayton brought in his garage tooling and showed them how he did it.
To this day, Chevrolet claims it invented the stamped-steel ball rocker arm, and its PR department makes no mention of Pontiac Engineering (though they do credit Clayton, specifically) as its inventor.
A search of U.S. patent records shows that Clayton had more than 20 patents on V-8 engine design, manufacturing, and lubrication. Let’s look at some of the most significant ones, as they relate to high-performance Pontiac V-8s.
U.S. Patent Number 2,902,014: Valve Actuating Mechanism for Engines
This design was pure genius, as it replaced the forged and machined rockers with very inexpensive stamped parts. His patent drawing also shows some other interesting cost savings, such as a pressed-in tapered stud instead of a tapped one, and a stamped hollow ball, which he figured out how to make. It’s another of his inventions that the manufacturing experts said was impossible to produce.
U.S. Patent Number 2,820,267: Cylinder Head / U.S. Patent Number 2902021: Cylinder Block
If you’re not familiar with how a foundry manufacturers blocks and heads, cores are used in the casting process to shape the internal cavities, such as the water jackets. Clayton put his inventive mind to work on these major castings and came up with a simplified method of making the cores for casting the block and heads. Earlier V-8s, such as the Oldsmobile and Cadillac versions, used more complicated cores, which raised the cost of the engine.
What was Clayton like as a person? I remember he was an open and friendly guy who used his charm to cultivate ideas amongst his associates. When I left Pontiac in 1973, he was the Division’s assistant chief engineer.
Title: Motor Engineer
Accomplishment: The Father of the Pontiac V-8
Of all the people who contributed to the design and development of the Pontiac V-8 engine, Mark Frank is at the top of the list. Mark started at Pontiac during the ’30s when Pontiac sold Flat-Head Straight-6s and Straight-8s. He became the motor engineer in 1942, and held that title during the Pontiac V-8’s inception through to production.
Assistant Engine Engineer Clayton Leach examines a set of 8-Lug wheels, which he designed.
When I started at Pontiac in 1957, Mark was the engine boss. He was very smart and capable, but didn’t make a lot of noise. Perhaps that’s why he didn’t get much publicity outside of the corporation. I was fearful of him when I started as a junior draftsman because he would come by every day to see what I was doing, but never said anything or made eye contact. One time when there was a design drawing of mine that he thought was incorrect, he didn’t say anything to me, but discussed it with the chief draftsman, who relayed Mark’s dissatisfaction with the drawing to me. I had to advance within Pontiac’s ranks before Mark started to speak to me directly.
Mark Frank’s 7,000-rpm camshaft
My next encounter with Mark was in 1965 when I was assigned to run the Pontiac Test Group at the GM Proving Grounds. The GTO was rapidly growing in popularity, and I built the first functional hoodscoop in the Proving Grounds shop. (The styling department knew how to make the hoodscoop look good, but I had to figure out how to actually make it work!) Our team was looking for ways to improve GTO engine performance, but with a usable rpm limit of about 5,500, we were limited.
One of my duties was to attend the monthly engine meetings. (About 50 engineers were at these meetings, even though the Pontiac V-8 engine was fully developed and in production for 10 years.) At one of the meetings I mentioned that we could improve the GTO’s performance if we could get a camshaft and valvetrain that would give us more than 5,500 rpm.
By then (April 1965 or shortly thereafter), Mark had been placed on “special assignment” (that’s General Motors-speak for “We want you to retire!”) by John DeLorean, and was replaced by Malcolm McKellar. Later, I found out why. Mark objected to putting the 389 engine in the Tempest, so DeLorean purposefully pushed him out of the way to prevent him from hindering Pontiac from ushering in the musclecar era.
You can view Clayton Leach’s patent (and other patents submitted on the behalf of Pontiac
As I exited the meeting, Mark came by and quietly told me that he would get me the high-performance camshaft we needed. About a month later it showed up in my office. We put it in our GTO test car and it immediately ran up to 7,000 rpm just like he promised.
It’s not hard to guess what happened next. Mark’s 7,000-rpm camshaft pushed a connecting rod past its metallurgical limits. In other words, it blew a rod. No one in the Engineering Group was interested in further work on it. I would have pursued it, but I was then assigned to Advanced Engineering.
If it had made it into production, would it have changed the course of Pontiac performance history? If so, Pontiac would have been forced to raise the durability of its V-8’s reciprocating assembly, which was only rated to 4,500 rpm for 100 hours non-stop at wide-open throttle. (Published redlines are higher because they are designed to allow the engine higher-rpm for short bursts of time—not 100 hours!) It was a cost the Division was unwilling to undertake to keep the GTO’s manufacturing expense under the bean counters’ radar.
The low-cost lifters that “won’t work”
This drawing accompanied Leach’s low-cost method to manufacture the Pontiac V-8 block.
At another of Pontiac’s engine meetings, a parts supplier came to us with a low-cost lifter, which they wanted Pontiac to buy. As I recall, Malcolm McKellar ran the meetings, and when the supplier was finished with the pitch, Malcolm asked Mark what he thought. Mark sat in the corner with his hands together like a church steeple, and then answered the question with three words: “It won’t work.” Despite Mark’s answer, cost was still king at Pontiac, so the supplier’s proposal had to be fully evaluated. After about six months of testing, Pontiac determined the low-cost lifters should not be put into production.
The Pontiac experimental X4 two-cycle 150ci engine
My next run-in with Mark was 1968, when I was working on the X4-2 cycle engine, which I designed while assigned to Pontiac Advanced Engineering. Mark visited the shop on a daily basis for an inspection. After many of his visits with no comments, he finally made eye contact with me and said, “It won’t work.”
Just like Pontiac didn’t listen about the low-cost lifters, I tried to explain how the X4 was simpler and lighter, better balanced, and had a lower manufacturing cost than an equivalent four-cylinder engine, but Mark was not impressed. He told me Charles “Boss” Kettering had done a similar engine back in the ’30s, and if I didn’t believe him, I could go to the Henry Ford Museum to see it hanging on the wall. I did and he was right.
That event broke the ice between Mark and me. On his future visits to the shop, he started telling me stories about how the Pontiac V-8 engine was engineered.
Kenneth B. Valentine
Accomplishment: Pontiac’s V-8 cast-iron cranks and connecting rods
Ken was the head metallurgist for Pontiac’s V-8’s cast reciprocating-assembly components, including the “N” and Armasteel steel cranks, the iron connecting rods, and the aluminum pistons. His duty was to make sure they met Pontiac’s standard engine-components durability test—again, that was 4,500 rpm for 100 hours at wide-open throttle. I asked him once why Pontiac didn’t use forged components inside of the engine. “The cast components pass the test and they cost considerably less,” he answered. “That’s all the Division cares about.”
A worker at the Pontiac foundry demonstrates his task to a group of sightseers on a factor
High-performance enthusiasts hate the concept, but cast components worked on millions of production engines by limiting the durability tests to 4,500 rpm.
Another of Ken’s innovations at Pontiac that I recall was induction- hardening the valveseats instead of installing separate seats. This was a great cost savings when unleaded fuel was introduced to Pontiacs in 1971.
Ken Valentine reminded me of my grandfather. He had a gentle nature, but a very sharp mind and great confidence in his own ability. He retired from General Motors before I left Pontiac in 1973.
Title: Assistant Experimental Engineer/Vehicle Test Engineer
Accomplishment: Engineer in charge of stock-car racing
In April 1, 1965, Mark Frank (center) was promoted to advanced power-plant engineer, Malco
In the summer of 1956, Russ was a young engineer working at the Proving Grounds testing the new Pontiac V-8 engine for durability and reliability. Pontiac’s leadership changed that summer when Bunkie Knudsen was made Division general manager and Pete Estes was made chief engineer. It turns out these guys were two of the most capable executives ever to be in the automobile business, and to Pontiac’s benefit, they were both car people. Their job was to bring Pontiac out of the doldrums and start selling cars that people would want.
As he tells it, Russ was doing his job one Saturday when Knudsen and Estes showed up and wanted to drive the prototype ’57 Pontiacs with the new 347ci V-8. Russ said they spent a couple hours racing each other on the Proving Ground roads. When they came back to the Pontiac garage, they told him that Pontiac was going stock-car racing, and Russ just became the engineer in charge of the program.
Russ Gee (far right) and foreman Mark Lightfoot (far left) present awards to two Pontiac e
Russ didn’t know much about racing, but he knew Pontiacs and had enthusiasm for getting things done. To gain knowledge about racing Pontiacs, he started running ’57s as fast as they would go. (He remembers getting them to go over 150 mph.) Of course, the early Pontiac overhead-valve V-8s were not designed for top-speed racing, so there were many failures. While Russ was solving the car problems, the Pontiac engine engineers were working on upping the horsepower. The result of the combined efforts of Russ and the other Pontiac engineers was that Pontiac ruled the NASCAR tracks from 1957 to 1962.
Russ left Pontiac in 1979 during Pontiac’s downslide, and transferred to Chevrolet to run its racing and high-performance programs. (I’ll discuss Russ more in “Pioneers of the Pontiac V-8, Part II: The Intermediate Years.”)
Pontiac metallurgist Ken Valentine (third from left) poses with secretary Ann Morgan at a
We’ve brought you the stories of the men, filled with attitude and dedication, who defined Pontiac Engineering during the early days of its overhead-valve V-8 and high-performance programs. In addition to these examples, there are hundreds of other stories by the many engineers who worked on the Pontiac V-8 engines. The excitement and success of Pontiacs in the ’60s is the direct result of their impassioned work under the enlightened management of Knudsen, Estes, and DeLorean. The desirability of these Pontiacs is a testimony of what can be accomplished when a talented group of engineers have a good leader.
HPP would like to thank Russ Gee, Marge Sawruk, Geneva Campbell, and Herb Adams for providing photos.